CLAIM_FH was added by NFSv4.1.  It is the same as CLAIM_NULL except that it
uses only current FH to identify the file to be opened.

The NFS client is using CLAIM_FH if the FH is available when opening a file.
Currently, we cannot get any delegation if we stat a file before open it
because the server delegation code does not recognize CLAIM_FH.

We tested this patch and found delegation can be handed out now when claim is
CLAIM_FH.

See http://marc.info/?l=linux-nfs&m=136369847801388&w=2 and
http://www.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues#New_open_claim_typesSigned-off-by: Ming Chen <mchen@cs.stonybrook.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

If a file is unlinked or renamed between the time when we do the local
open and the time when we get the delegation, then we will return to the
client indicating that it holds a delegation even though the file no
longer exists under the name it was open under.

But a client performing an open-by-name, when it is returned a
delegation, must be able to assume that the file is still linked at the
name it was opened under.

So, hold the parent i_mutex for longer to prevent concurrent renames or
unlinks.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This is basically a no-op, to simplify a following patch.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

As far as I can tell, this list is used only under the state lock, so we
may as well do this in the simpler order.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Replace hardcoded lowest common multiple algorithm by the lcm()
function in kernel lib.
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

A struct svc_fh is 320 bytes on x86_64, it'd be better not to have these
on the stack.

kmalloc'ing them probably isn't ideal either, but this is the simplest
thing to do.  If it turns out to be a problem in the readdir case then
we could add a svc_fh to nfsd4_readdir and pass that in.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We stick an extra svc_fh in nfsd3_readdirres to save the need to
kmalloc, though maybe it would be fine to kmalloc instead.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We can simplify the idmapping code if it does its own encoding and
returns nfs errors.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

There's a simpler way to write this.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Remove some pointless goto's.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This confuses me every time.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

As a temporary fix, nfsd was breaking all leases on unlink, link,
rename, and setattr.

Now that we can distinguish between leases and delegations, we can be
nicer and break only the delegations, and not bother lease-holders with
operations they don't care about.

And we get to delete some code while we're at it.

Note that in the presence of delegations the vfs calls here all return
-EWOULDBLOCK instead of blocking, so nfsd threads will not get stuck
waiting for delegation returns.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

If failed after calling alloc_session but before init_session, nfsd will call __free_session to
free se_slots in session. But, session->se_fchannel.maxreqs is not initialized (value is zero).
So that, the memory malloced for slots will be lost in free_session_slots for maxreqs is zero.

This path sets the information for channel in alloc_session after mallocing slots succeed,
instead in init_session.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We can achieve the same result with a cmpxchg(). This also fixes a
potential race in use_gss_proxy(). The value of sn->use_gss_proxy could
go from -1 to 1 just after we check it in use_gss_proxy() but before we
acquire the spinlock. The procfile write would end up returning success
but the value would flip to 0 soon afterward. With this method we not
only avoid locking but the first "setter" always wins.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

An nfsd thread can call use_gss_proxy and find it set to '1' but find
gssp_clnt still NULL, so that when it attempts the upcall the result
will be an unnecessary -EIO.

So, ensure that gssp_clnt is created first, and set the use_gss_proxy
variable only if that succeeds.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

It doesn't make much sense to make reads from this procfile hang. As
far as I can tell, only gssproxy itself will open this file and it
never reads from it. Change it to just give the present setting of
sn->use_gss_proxy without waiting for anything.

Note that we do not want to call use_gss_proxy() in this codepath
since an inopportune read of this file could cause it to be disabled
prematurely.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Without CONFIG_NFSD_V3, compile will get warning as,

fs/nfsd/nfssvc.c: In function 'nfsd_svc':
>> fs/nfsd/nfssvc.c:246:60: warning: array subscript is above array bounds [-Warray-bounds]
        return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL);
                                                               ^
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

When starting without nfsv2 and nfsv3, nfsd does not need to start
lockd (and certainly doesn't need to fail because lockd failed to
register with the portmapper).
Reported-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSv4 clients can contact port 2049 directly instead of needing the
portmapper.

Therefore a failure to register to the portmapper when starting an
NFSv4-only server isn't really a problem.

But Gareth Williams reports that an attempt to start an NFSv4-only
server without starting portmap fails:

  #rpc.nfsd -N 2 -N 3
  rpc.nfsd: writing fd to kernel failed: errno 111 (Connection refused)
  rpc.nfsd: unable to set any sockets for nfsd

Add a flag to svc_version to tell the rpc layer it can safely ignore an
rpcbind failure in the NFSv4-only case.
Reported-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

the length for backchannel checking should be multiplied by sizeof(__be32).
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

check_forechannel_attrs gets drc memory, so nfsd must put it when
check_backchannel_attrs fails.

After many requests with bad back channel attrs, nfsd will deny any
client's CREATE_SESSION forever.

A new test case named CSESS29 for pynfs will send in another mail.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

commit 5b6feee9 forgot
recording the back channel attrs in nfsd4_session.

nfsd just check the back channel attars by check_backchannel_attrs,
but do not  record it in nfsd4_session in the latest kernel.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Since defined in Linux-2.6.12-rc2, READTIME has not been used.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

host_err was only used for nfs4_acl_new.
This patch delete it, and return nfserr_jukebox directly.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Get rid of the extra code, using nfsd4_encode_noop for encoding destroy_session and free_stateid.
And, delete unused argument (fr_status) int nfsd4_free_stateid.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We should use XDR_LEN to calculate reserved space in case the oid is not
a multiple of 4.

RESERVE_SPACE actually rounds up for us, but it's probably better to be
careful here.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

commit 557ce264
"nfsd41: replace page based DRC with buffer based DRC"
have remove unused nfsd4_set_statp, but miss the function definition.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

commit 58cd57bf
"nfsd: Fix SP4_MACH_CRED negotiation in EXCHANGE_ID"
miss calculating the length of bitmap for spo_must_enforce and spo_must_allow.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

There is an inconsistency in the handling of SUID/SGID file
bits after chown() between NFS and other local file systems.

Local file systems (for example, ext3, ext4, xfs, btrfs) revoke
SUID/SGID bits after chown() on a regular file even if
the owner/group of the file has not been changed:

~# touch file; chmod ug+s file; chmod u+x file
~# ls -l file
-rwsr-Sr-- 1 root root 0 Dec  6 04:49 file
~# chown root file; ls -l file
-rwxr-Sr-- 1 root root 0 Dec  6 04:49 file

but NFS doesn't do that:

~# touch file; chmod ug+s file; chmod u+x file
~# ls -l file
-rwsr-Sr-- 1 root root 0 Dec  6 04:49 file
~# chown root file; ls -l file
-rwsr-Sr-- 1 root root 0 Dec  6 04:49 file

NFS does that only if the owner/group has been changed:

~# touch file; chmod ug+s file; chmod u+x file
~# ls -l file
-rwsr-Sr-- 1 root root 0 Dec  6 05:02 file
~# chown bin file; ls -l file
-rwxr-Sr-- 1 bin root 0 Dec  6 05:02 file

See: http://pubs.opengroup.org/onlinepubs/9699919799/functions/chown.html

 "If the specified file is a regular file, one or more of
 the S_IXUSR, S_IXGRP, or S_IXOTH bits of the file mode are set,
 and the process has appropriate privileges, it is
 implementation-defined whether the set-user-ID and set-group-ID
 bits are altered."

So both variants are acceptable by POSIX.

This patch makes NFS to behave like local file systems.
Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

hex_pack_byte() is a fast way to convert a byte in its ASCII representation. We
may use it instead of custom approach.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Currently when we are processing a request, we try to scrape an expired
or over-limit entry off the list in preference to allocating a new one
from the slab.

This is unnecessarily complicated. Just use the slab layer.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The Linux NFS server replies among other things to a "Check access permission"
the following:

NFS:    File type = 2 (Directory)
NFS:    Mode = 040755

A netapp server replies here:
NFS:    File type = 2 (Directory)
NFS:    Mode = 0755

The RFC 1813 i read:
   fattr3

      struct fattr3 {
         ftype3     type;
         mode3      mode;
         uint32     nlink;
...
For the mode bits only the lowest 9 are defined in the RFC

As far as I can tell, knfsd has always done this, so apparently it's harmless.
Nevertheless, it appears to be wrong.

Note this is already correct in the NFSv4 case, only v2 and v3 need
fixing.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This has gone a little stale.
Reported-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The DRC code will attempt to reuse an existing, expired cache entry in
preference to allocating a new one. It'll then search the cache, and if
it gets a hit it'll then free the cache entry that it was going to
reuse.

The cache code doesn't unhash the entry that it's going to reuse
however, so it's possible for it end up designating an entry for reuse
and then subsequently freeing the same entry after it finds it.  This
leads it to a later use-after-free situation and usually some list
corruption warnings or an oops.

Fix this by simply unhashing the entry that we intend to reuse. That
will mean that it's not findable via a search and should prevent this
situation from occurring.

Cc: stable@vger.kernel.org # v3.10+
Reported-by: Christoph Hellwig <hch@infradead.org>
Reported-by: g. artim <gartim@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>